![]() ![]() ![]() Last two digits describing maximum thickness of the airfoil as percent of the chord.Second digit describing the distance of maximum camber from the airfoil leading edge in tenths of the chord.First digit describing maximum camber as percentage of the chord.The NACA four-digit wing sections define the profile by: These figures and shapes transmitted the sort of information to engineers that allowed them to select specific airfoils for desired performance characteristics of specific aircraft. Engineers could quickly see the peculiarities of each airfoil shape, and the numerical designator ("NACA 2415," for instance) specified camber lines, maximum thickness, and special nose features. By 1929, Langley had developed this system to the point where the numbering system was complemented by an airfoil cross-section, and the complete catalog of 78 airfoils appeared in the NACA's annual report for 1933. According to the NASA website:ĭuring the late 1920s and into the 1930s, the NACA developed a series of thoroughly tested airfoils and devised a numerical designation for each airfoil - a four digit number that represented the airfoil section's critical geometric properties. NACA initially developed the numbered airfoil system which was further refined by the United States Air Force at Langley Research Center. The NACA airfoil series is a set of standardized airfoil shapes developed by this agency, which became widely used in the design of aircraft wings. It played a crucial role in advancing aviation technology, including the development of airfoils, which are the cross-sectional shapes of wings and other aerodynamic surfaces. federal agency founded in 1915 to undertake, promote, and institutionalize aeronautical research. NACA stands for the National Advisory Committee for Aeronautics, which was a U.S. thickness 5: Camber 6: Upper surface 7: Trailing edge 8: Camber mean-line 9: Lower surface Profile lines – 1: Chord, 2: Camber, 3: Length, 4: Midline A: blue line = chord, green line = camber mean-line, B: leading-edge radius, C: xy coordinates for the profile geometry (chord = x axis y axis line on that leading edge) Left click over the numeric value and a text box will open, type the desired value, close the window, and the value will be updated.Wing shape Profile geometry – 1: Zero-lift line 2: Leading edge 3: Nose circle 4: Max. Values used to define the thickness and camber line may also be entered manually. Camber line slider bars are only used for the four digit airfoils, five digit airfoil camber lines are the NACA default values. The slider bars are used to change the thickness and camber line parameters. ![]() Various modification of the mean line, leading edge radius of curvature, and trailing edge angle were made as a part of the NACA research however, these are not implemented in AeroFoil. Where x u and y u are the upper surface coordinates, x l and y l are the lower surface coordinates, and θ is the angle between the mean line and the airfoil chord. The mean line and thickness distribution are combined to give the airfoil shape by the following: Values of k 1 were calculated to result in a design lift coefficient of 0.3. Values of m were chosen to give five positions of p, the maximum camber, of 0.05c, 0.10c, 0.15c, 0.20c, and 0.25c, where c in the airfoil chord. Y c = k 1 m 3 (1 - x) from x = m to x = 1 The camber line for a 5-digit airfoil is given by: Where m is the maximum ordinate of the mean line expressed as a fraction of the chord and p is the chordwise location of the maximum ordinate. Y c = m / (1 - p) 2 aft of the maximum ordinate Y c = m (2 p x - x 2) / p 2 forward of the maximum ordinate, and The camber line for a 4-digit airfoil is given by: Where t is the thickness expressed as a fraction of the chord. The available data was used to create an equation for a thickness distribution that was similar in turn to those airfoils. In the early 30’s, NACA found that the successful airfoils of the time had very similar thickness distributions after their camber lines were straightened. NACA 4 and 5 digit wing sections combine a thickness distribution with a camber line. AeroFoil Help NACA 4 and 5 digit Airfoils ![]()
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